LSAT Explanation PT 39, S4, Q12: The higher a dam, the more

LSAT Question Stem

Which one of the following, if true, most helps to resolve the apparent paradox? 

Logical Reasoning Question Type

This is a Paradox question. 

Correct Answer

The correct answer to this question is C. 

LSAT Question Complete Explanation

Let's first analyze the passage and break down the information given. The passage states that the higher a dam is, the more exposed it is to forces that can cause it to collapse. It then mentions that more than half of the world's arch dams are over 100 meters high. However, all six arch dam collapses that have occurred in the past 40 years have been in arch dams under 100 meters high. This presents a paradox: if higher dams are more exposed to forces that can cause collapse, why have all the collapses occurred in lower dams?

The question type for this problem is Paradox, which means we are asked to find an answer choice that helps resolve the apparent paradox. Now, let's go through each answer choice and evaluate how well it resolves the paradox.

a) The higher a dam must be, the greater the likelihood that it will be built as an arch dam.

- This answer choice doesn't help resolve the paradox. It only states that higher dams are more likely to be built as arch dams, but it doesn't explain why lower arch dams are the ones collapsing instead of the higher ones.

b) Arch dams are generally more complicated and more costly to construct than other types of dams of comparable size.

- This answer choice is irrelevant to the paradox. It compares arch dams to other types of dams in terms of complexity and cost, but it doesn't explain why lower arch dams are collapsing instead of higher ones.

c) The larger the structure, the more careful the attention it received in design and construction.

- This answer choice resolves the paradox. It states that larger structures (higher arch dams) receive more careful attention in their design and construction. This implies that smaller structures (lower arch dams) receive less careful attention, which could explain why they are the ones collapsing instead of the higher ones. This is the correct answer.

d) The basic engineering principles behind the design and construction of arch dams have been known for more than 100 years.

- This answer choice doesn't help resolve the paradox. It provides information about the history of arch dam engineering, but it doesn't explain why lower arch dams are collapsing instead of higher ones.

e) Arch dams under 100 meters high are less subject to collapse than are dams of other types also under 100 meters high.

- This answer choice is out of scope. It compares lower arch dams to other types of lower dams in terms of their likelihood to collapse, but it doesn't explain why lower arch dams are collapsing instead of higher ones.

In summary, the correct answer is C, as it explains that larger structures receive more careful attention in design and construction, which could explain why higher arch dams are not collapsing, while lower arch dams are.